The difficulty of having sheep move in a selected path and especially along a chute is very well known and extensively documented.
Many reasons have been put forward as to why sheep will not willingly move forwardly in a chute, but it is now well known that they will sometimes attempt almost impossible actions to withdraw from a chute for no apparent reason and, certainly, to have a sheep willingly move along a chute would be of considerable assistance to all who need to handle sheep.
I have previously proposed an arrangement that has had some considerable value which is in the form of a barrier which is held in such a way that a sheep, perhaps by curiosity, will tend to look thereunder and will upon such action lift the barrier and the barrier will gently rest upon the sheep, first its head, and thereafter its back, and interestingly, when the sheep turns to look behind, its view will thereafter be blocked by the barrier.
This device has had considerable value.
However, while this device does assist, it will not in itself cause the sheep to move forwardly along a chute and especially will not activate these upon any selected action by an operator.